Plane carrying top Polish government officials went to Russia to go to the memorial or w/e for a Soviet massacre of Polish officers, as the plane was landing it crashed and all 97 aboard died.

"The crash devastated the upper echelons of Poland's political and military establishments. On board were the army chief of staff, national bank president, deputy foreign minister, army chaplain, head of the National Security Office, deputy parliament speaker, civil rights commissioner and at least two presidential aides and three lawmakers, the Polish foreign ministry said."

Also, the President of Poland died in the crash. What a shitty day for Poland, losing the hierarchy of you're government doesn't play out too well...